Cutting Mortises

[Smoothjazz077]

I currently cut out my mortises by hand using a Mortise Chisel. However, I was watching a Paul Sellers video the other day, and he did a demo cutting a mortise with a mortise chisel and then a mortise with a bevel edge chisel. He actually put a piece of glass against the stock to show what the inside of the mortise looked like as he was cutting and clearing away the wood chips.
I have never used a bevel edge chisel to cut a mortise, but I was impressed how quickly and cleanly Sellers did it in the video. He did mention more than once that you need to take notice and not over stress the bevel edge chisel as not to bend it. I was just curious if anyone else uses this method for cutting mortises. I am looking to give it a try this week.

Scott woodworking Homepage

[Window Guy]

I gave a nice Delta Mortiser like the one shown in the S&S section. However I cut mine by hand like Paul has demonstrated, my first attemp was my Paul Sellers style bench. I like doing them by hand and with a little practice it is not that hard.

Steve

[DaveParkis]

I use mortise chisels. I've seen to many pics of broken bevel edge chisels to try that method. I think that if you go slowly enough, it would be okay, but I prefer to just bash it with a mortise chisel and be done.

[Alex Grigoriev]

Tip on cleaning the mortise bottoms:

Take a cheap chisel (low hardness) of appropriate width and make a burr on its edge. Actually bend a little bit. That will allow to scrape the mortise bottom easily. You can take the chisel to a high speed grinder to make it lose its temper a bit; that will let you make a bigger hook.

[AHill]

Nice video. Given the right bevel edge chisel, it works just fine. I first saw the glass sided video when attending the very first WIA. Frank Klausz cut the mortise, and Roy Underhill held the camera. Klausz used a mortise chisel. I no longer cut mortises by hand, because I'm horrible at cutting the tenons. I use a tailed tool to do loose tenon mortises now.

[Bibliophile 13]

I learned that method from him, but I always had problems getting a good, clean mortise. Then I got myself a real mortise chisel, and my mortises immediately got cleaner. I think there are a couple reasons:

My bevel-edged chisel never wanted to stay straight. With successive cuts, it would want to rotate one direction or the other, resulting in a very jagged mortise wall. A mortise chisel is much easier to hold straight. Also, my bevel-edged chisel also tended to get caught once the mortise got deep, especially because the lands didn't go all the way to the back of the chisel. So it was like driving a square nail into the wood each time. The mortise chisel, however, doesn't have a rectangular cross-section. It's a trapezoid. That means there's some wiggle room when you drive the chisel in, and as you move it back and forth, it scrapes the walls of the mortise, leaving a cleaner surface than the bench chisel does.

I know you can chop a good mortise with a bench chisel, and I've done it. But there'a a reason the mortise chisel has remained the standard tool for mortising by hand. It really is the best tool for the job.

[Peter Tremblay]

Bibliophile 13 said:

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My bevel-edged chisel never wanted to stay straight.

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I've had the same problem but then I watched the video and I think I see something interesting.

His beveled edge chisel has a square-ish handle. I wonder if that handle "feel" helps him register it correctly and keep it straight.

Just a thought.

I haven't chopped a mortise in a while with a bevel edged chisel but this video makes me want to try it.

[wmickley]

I used a bevel edge chisel to cut mortises until I bought a mortise chisel forty years ago. I also used socket firmer chisels until I rounded out my set of mortise chisels. I can make a mortise with any chisel, but mortising with a bevel edge chisel is clumsy and sloppy.

It is somewhat easier to mortise with the glass. You are only doing half as much work, and you have the glass to register against so placement of the chisel is easier.

I have worked for decades with $124 worth of bench planes (5 planes) and $40 worth of saws and backsaws (7 saws). I do not recommend scrimping on mortise chisels.

Warren

[Ricky]

Paul can probably cut a mortise using a pocket knife.

I'll stick with the mortise chisel.

[Derek Cohen]

The mortice chisels I use have two (three?) cutting edges: the obvious one is at the bevel end. The other is the sharp lands at the back of the blade (often missing on vintage mortice chisels). These slice the side walls for a clean entry for the tenon. The deep mortice blade helps avoid twisting and keeps the blade aligned. A bevel edged chisel has none of these attributes and, while it can do the job (so can an ice pick), it makes the task less efficient.

Regards from Perth

Derek